1. Field of the Invention
The invention relates generally to a medical device, and more particularly to a retrieval device for capturing and/or removing objects from within a body cavity.
2. Description of the Related Art
Medical retrieval devices used to remove objects from body cavities by inserting the retrieval device, usually by way of a catheter, into a body cavity, engaging the object using the retrieval device, and removing the object using the retrieval device, or at least moving the object to more accessible location within the body. The object to be retrieved can be a natural formation in the body, such as a blood clot, kidney stone, gall stone, or polyp or a foreign item such as a coil, stent, catheter, or guidewire. The three most common retrieval devices are basket retrieval devices, forceps retrieval devices, and snare loop retrieval devices.
A common application of medical retrieval devices is removing objects from the neurovasculature during a medical procedure, for example, removing clots during the setting of acute stroke or removing displaced coils used in the management of intracranial aneurysm. Yet, the neurovasculature poses a problem for known medical retrieval devices since the neurovasculature is smaller and more tortuous than other body cavities. Forceps retrieval devices are used primarily in larger cavities and are typically too large and rigid to be used in the neurovasculature. Other basket and snare loop retrieval devices are too stiff for neurovasculature application. The stiffness or rigidity of known medical retrieval devices is especially problematic at the leading distal end of the medical retrieval device. As the retrieval device is threaded through the vessel, the leading distal end can damage the delicate walls of the vasculature. However, a certain amount of stiffness for the proximal end of the retrieval device is necessary so that the user (i.e. physician) can manipulate and guide the retrieval device through the body cavity.